1. Field of the Invention
The present invention relates in general to an improved solution for removing stains from hard surfaces, carpets and fabrics, that is easier to handle and store, and is also environmentally friendly.
2. Background Art
Stain removing solutions have been known and used in a variety of applications, including removing stains from hard surfaces, such as wooden and concrete floors, painted walls, stone countertops, floor and bath tiles, as well as composite or laminated materials that are on various household and office surfaces. Stain removing solutions are also called spot removers when being used to remove stains from carpets, rugs, and other fabrics, such as clothing, furniture, upholstery, and drapery. As part of daily household life, unwanted stains appear on such surfaces and materials, through food and drink spills, tracking of outdoor contaminants by dirty shoes and animals, bleed-through or over-writing from pens, markers or crayons, accidents resulting in the spill of human or animal blood or bodily waste, or spills of paint or nail polish, whose coloring went beyond its intended use and resulted in a stained or soiled hard surface, carpet or fabric. Typically, a small amount of a stain removing solution sprayed onto the surface may remove the stain, which is then wiped away using a cloth or paper towel.
Stain removing solutions have traditionally contained a higher pH level, such as 9.0 and higher. While higher pH solutions have been effective at removing stains, their high pH levels pose problems for the cleaner, as well as for the surface that is being cleaned. First of all, direct contact with a high pH solution can dry out or even burn the skin; protective gloves must be worn by the user. Furthermore, high pH solutions can also corrode hard surfaces and fabric while removing the stain. Depending on the severity of the stain and the type of surface or material being treated, a high amount of solution may be necessary to remove the stain. Prolonged exposure to a high pH cleaning solution can often result in corrosion, discoloration, or otherwise damage to more delicate surfaces, and for these reasons, is not recommended for use at all on delicate fabrics such as silks. For such applications, spot removing solutions are used. However, such solutions are not as effective at removing stains, and are often inconvenient for the user, who must purchase an additional stain removing solution for this purpose.
Stain removing solutions also are known to contain surfactants. However, many surfactants that are currently used in stain removing solutions solidify, or gel, at colder temperatures, causing the solution to separate, and the surfactant to fall to the bottom of the solution. If this should happen, such as during transport or storage of the solution during winter months, the solution may no longer be effective as a stain remover. Even if the temperature later rises, the surfactant is unlikely to thoroughly mix inside the container, such that when the solution is dispensed, it may or may not contain an effective amount of the surfactant to remove the stain.
Stain removing solutions are also known to contain solvents to dislodge the stain from the surface or fabric. Many solvents that are currently used in stain removing solutions have a high vapor pressure. Solvents having a high vapor pressure are known to be effective at dislodging a stain, especially at high pH levels, but not without considerable drawbacks. First, such solvents quickly flash off from the solution after they are applied, leaving the solution unable to penetrate a deep stain. Second, these solvents often smear or “ring” part of the stain onto another portion of the surface or fabric, rather than remove it from the surface or fabric completely. Third, solvents with a high vapor pressure often emit an odor that is unpleasant for the user. Finally, such solvents often emit high amounts of volatile organic compounds (VOCs) that are the subject of increasing regulation and public concern, which limit their use in household products.
It has also become important for stain removing solutions to be formulated in such a way as to have less impact on the environment. One way in which this is encouraged is through a program of the United States Environmental Protection Agency, known as the Design for the Environment Program (“DfE”). DfE certifies “green” cleaning products through the Safer Product Labeling Program. Another is through state regulatory bodies, such as the California Air Resources Board (“CARB”). Either through regulation, or through certification, these bodies set out standards for achieving environmentally friendly cleaning products. Among the standards, are the desire for a solution that is not as corrosive as prior art solutions, one having a more neutral pH level. Further, the solution must minimize the emissions of VOCs, as well as the percentage of solvent that it may contain.
Accordingly, it is desirable to provide an effective stain removing solution which is less corrosive than existing solutions for safer handling by the user, and to reduce the corrosive effects on the applied surfaces and fabrics.
It is further desirable to provide an effective stain removing solution, that may be transported and stored at cold temperatures, without concern of a key ingredient separating from the solution.
It is yet further desirable to find a single stain removing solution which may be applied to hard surfaces and delicate fabrics alike, and which meets any and all applicable environmental standards and regulations, with a specific combination of surfactants, solvents and hydrotropes—all of which act in a synergistic manner to improve their effectiveness in removing stains.